This invention relates to a spring suspension for a trailed vehicle. It has been found that, with trailed vehicle beam axle suspension systems currently used a slight backward displacement of a wheel in the opposite direction to that of the trailed motion occurs when a force acts on the wheel to displace it upwardly from its undisturbed position. This introduces a steering effect, since both wheels are interconnected by the axle, tending to increase the effects on the trailed vehicle of the displacing force.